Liquid crystallinity in flexible and rigid rod polymers

Journal Article · Wed Mar 08 04:00:00 EST 2000 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.481039· OSTI ID:20215601

Pickett, Galen T ^[1]; Schweizer, Kenneth S ^[2]

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1. Department of Physics and Astronomy, California State University, Long Beach, 1250 Bellflower Boulevard, Long Beach, California 90840 (United States)
2. Departments of Materials Science and Engineering and Chemistry, and Materials Research Laboratory, University of Illinois, 1304 West Green Street, Urbana, Illinois 61801 (United States)

We apply an anisotropic version of the polymer reference interaction site model (PRISM) integral equation description of flexible polymers to analyze athermal liquid crystallinity. The polymers are characterized by a statistical segment length, {sigma}{sub o}, and by a physical hard-core thickness, d, that prevents the overlap of monomers on different chains. At small segment densities, {rho}, the microscopic length scale d is irrelevant (as it must be in the universal semidilute regime), but becomes important in concentrated solutions and melts. Under the influence of the excluded volume interactions alone, the chains undergo a lyotropic, first-order isotropic-nematic transition at a concentration dependent upon the dimensionless ''aspect ratio,'' {sigma}{sub o}/d. The transition becomes weaker as d{yields}0, becoming second order, as has been previously shown. We extend the theory to describe the transition of rigid, thin rods, and discuss the evolution of the anisotropic liquid structure in the ordered phase. (c) 2000 American Institute of Physics.

• OSTI ID: 20215601
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 10 Vol. 112; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
ANISOTROPY
FLEXIBILITY
LIQUID CRYSTALS
PHASE TRANSFORMATIONS
POLYMERS
STRUCTURE FACTORS
THEORETICAL DATA